Multiplexed pathlength resolved noninvasive analyzer apparatus and method of use thereof

Abstract

A noninvasive analyzer apparatus and method of use thereof is described using one or a plurality of sample illumination zones coupled to at least one two-dimensional detector array monitoring a plurality of detection zones. Control of illumination times and/or patterns along with selected detection zones yields pathlength resolved groups of spectra. Sectioned pixels and/or zones of the detector are optionally filtered for different light throughput as a function of wavelength. The pathlength resolved groups of spectra are subsequently analyzed to determine an analyte property. Optionally, in the mapping and/or collection phase, incident light is controllably varied in time in terms of any of: sample probe position, incident light solid angle, incident light angle, depth of focus, energy, intensity, and/or detection angle. Optionally, one or more physiological property and/or model property related to a physiological property is used in the analyte property determination.

The invention claimed is: 
     
       1. An apparatus for noninvasive estimation of an analyte concentration of a human subject, comprising:
 a near-infrared noninvasive analyzer, comprising:
 a near-infrared source; 
 a photon transport system configured to transport photons from said near-infrared source to an illumination zone; 
 a two-dimensional planar transmittance filter array comprising:
 a first filter comprising a first fifty percent cut-on transmittance inflection point at a first wavelength in a range of 1200 to 2500 nanometers; 
 a second filter comprising a second fifty-percent cut-on transmittance inflection at a second wavelength, said second wavelength at least one hundred nanometers shorter than said first wavelength, 
 said first filter positioned closer to the illumination zone than said second filter; and 
 a detector, said detector configured to detect a sub-set of the photons after the photons undergo diffuse reflection and arrive at a detection zone, both the illumination zone and the detection zone in proximate contact with the subject during use, 
 said two-dimensional planar transmittance filter orientated substantially parallel to a line from the illumination zone to the detection zone. 
 
 
 
     
     
       2. The apparatus of  claim 1 , said two-dimensional planar transmittance filter array further comprising:
 a third filter comprising a third cut-on transmittance inflection point at a third wavelength in a range of 1100 to 1900 nanometers, said third wavelength at least one hundred nanometers shorter than said second wavelength, 
 said second filter positioned closer to the illumination zone than said third filter. 
 
     
     
       3. The apparatus of  claim 1 , said analyzer further comprising:
 at least one two-dimensional near-infrared detector array configured to detect diffusely reflected photons from a detection zone proximate the subject interface zone, said two-dimensional near-infrared detector array within ten centimeters of the illumination zone during use; and 
 a processor configured to convert signals from said two-dimensional near-infrared detector array into a vibrational spectroscopy reading. 
 
     
     
       4. The apparatus of  claim 3 , said two-dimensional near-infrared detector array further comprising:
 a two-dimensional array of detector wells, wherein a first photon facing element of said array of detector wells comprises a first total surface area, wherein a second photon facing element of said array of detector wells comprises a second total surface area, said second total surface area at least fifty percent larger than said first total surface area. 
 
     
     
       5. The apparatus of  claim 3 , said two-dimensional near-infrared detector array comprising:
 a first detector positioned at a first radial distance from a center of the illumination zone, said first detector comprising a first surface area; and 
 a second detector positioned at a second distance from the center of the illumination zone, said second detector comprising a second surface area, 
 said second distance greater than said first distance, and 
 said second surface area at least fifty percent larger than said first surface area. 
 
     
     
       6. The apparatus of  claim 1 , said near-infrared source further comprising:
 a broadband source configured to provide wavelengths of photons varying by at least twenty nanometers at least in a range of 1500 to 1800 nanometers, the photons comprising the diffusely reflected photons detected by said two-dimensional detector array during use. 
 
     
     
       7. The apparatus of  claim 1 , said two-dimensional detector array further comprising:
 at least three columns of detector elements and at least three rows of detector elements, said two-dimensional detector array comprising at least indium, gallium, and arsenide. 
 
     
     
       8. The apparatus of  claim 1 , said two-dimensional detector array further comprising:
 at least one curved path of at least ten detector elements, said at least ten detector elements electrically wired for serial readout. 
 
     
     
       9. The apparatus of  claim 1 , said near-infrared noninvasive analyzer further comprising:
 a first optic configured to guide a first mean optical path along a first angle, said first angle: (1) intersecting the illumination zone and (2) comprising a vector component toward said illumination zone; and 
 a second optic configured to guide a second mean optical path along a second angle: (1) intersecting the illumination zone and (2) comprising a vector component away from said illumination zone, wherein substantially no photons from said near-infrared source passing through said first optic to the subject pass through the second optic to the subject. 
 
     
     
       10. The apparatus of  claim 3 , said at least one two-dimensional near-infrared detector array comprising:
 a first m by n detector array positioned along a first vector from a center point of the detection zone; 
 a second x by y detector array positioned along a second vector from the center point of the detection zone, 
 wherein m, n, x, and y comprises positive integers of at least two, 
 wherein said first vector and said second vector form an angle greater than twenty degrees and less than three hundred forty degrees. 
 
     
     
       11. The apparatus of  claim 1 , said photon transport system further comprising:
 a first optic of said two-dimensional planar transmittance filter array coupled to a first linear array of detector elements; and 
 a second optic of said two-dimensional planar transmittance filter array coupled to a second linear array of detection elements, 
 said first optic not optically coupled to said second linear array of detector elements, 
 said first optic comprising a first transmittance differing from a second transmittance of said second optic by at least twenty percent at at least three wavelengths separated from each other by at least one hundred nanometers in a range of 1100 to 2500 nm. 
 
     
     
       12. The apparatus of  claim 1 , further comprising:
 a housing, said housing containing each of said source, said two-dimensional planar transmittance filter array, and said two-dimensional detector array, 
 said two-dimensional planar transmittance filter array co-planar and substantially contacting at least eighty percent of a detector element surface of said two-dimensional detector array, 
 said two-dimensional detector array positioned within ten centimeters of the subject during use. 
 
     
     
       13. The apparatus of  claim 1 , wherein each element of said two-dimensional planar transmittance filter array optically couples to at least one detector element of said two-dimensional detector array. 
     
     
       14. The apparatus of  claim 1 , further comprising:
 a two-dimensional array of discrete illumination optics, said discrete illumination optics individually coupled to said near-infrared source, said two-dimensional array of discrete illumination optics configured to provide photons to the illumination zone. 
 
     
     
       15. A method for noninvasive estimation of an analyte concentration of a human subject, comprising, comprising the steps of:
 providing a near-infrared noninvasive analyzer, comprising:
 a near-infrared source; 
 a photon transport system; and 
 a two-dimensional planar transmittance filter array comprising:
 a first filter comprising a first fifty percent cut-on transmittance inflection point at a first wavelength in a range of 1200 to 2500 nanometers; 
 a second filter comprising a second fifty-percent cut-on transmittance inflection at a second wavelength, said second wavelength at least one hundred nanometers shorter than said first wavelength, 
 said first filter positioned closer to the illumination zone than said second filter; and 
 
 
 transporting the photons from said near-infrared source through an illumination zone; 
 passing the photons through said two-dimensional planar transmittance filter array; and 
 detecting a sub-set of the photons, with a detector, after the photons undergo diffuse reflection and arrive at a detection zone, both the illumination zone and the detection zone proximately contacting the subject, 
 said two-dimensional planar transmittance filter orientated substantially parallel to a line from the illumination zone to the detection zone. 
 
     
     
       16. The method of  claim 15 , said two-dimensional planar transmittance filter array further comprising:
 a third filter comprising a third cut-on transmittance inflection point at a third wavelength in a range of 1200 to 2500 nanometers, said third wavelength at least one hundred nanometers shorter than said second wavelength, 
 said second filter positioned closer to the illumination zone than said third filter. 
 
     
     
       17. The method of  claim 16 , further comprising a step of:
 processing said set of signals using a correlation vector, said correlation vector comprising: a first signal associated with said first filter, a second signal associated with said second filter, and a third signal associated with said third filter. 
 
     
     
       18. The method of  claim 15 , further comprising the step of:
 the human subject wearing at least one element of said near-infrared noninvasive analyzer. 
 
     
     
       19. The method of  claim 15 , further comprising the step of:
 using said near-infrared noninvasive analyzer in an integrated insulin pump continuous delivery system.